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gas tank welding

blazinzuk

blazinzuk

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any better way to do it?

Need to weld the filler neck back in place on Hortons gas tank.

I usually fill with water and weld. Better way?
 
Take it out, toss in match. Watch the jet engine fire go off... Then weld :thumb:
 
I sometimes have to cut and weld on locomotive diesel tanks up to 4500 gallon capacity, sometimes full and sometimes almost empty. I just purge them for a few minutes with C02 welding gas before and during the process. the first few times was kinda scary but now it's routine.

I haven't done this with gasoline tanks though...
 
Gas is a little different. If you aren't careful you will end up with flammable water. As long as your not injured or anything kind of cool. But not so cool when you get injured.
 
I was always told to fill them with water then empty them and weld away. Once you fill them back up with fuel the water issue is gone.
 
blazinzuk said:
Yep. But by dang I is gonna weld it LOL

I don't know what type of solder is used? I don't know much about soldering. Is there a kind you use that is made for this?
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Lead solder would probably be best. Like the kind used for body work. Still involves fire though.

I'd personally reccomend you get rid of that silly K5 tank and go with a proper fuel cell that won't spill gas all over the place whenever you get slightly off camber ;)
 
Russell said:
Lead solder would probably be best. Like the kind used for body work. Still involves fire though.

I'd personally reccomend you get rid of that silly K5 tank and go with a proper fuel cell that won't spill gas all over the place whenever you get slightly off camber ;)
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You wanna loan me 300 bucks or so LOL

The spilling problem was the filler neck I just hadn't really noticed it before. Gonna try to get a sealed cap and a separate vent tube, put a roll over valve in the vent tube so that if I roll it won't leak.
 
There are videos on youtube of the "fire" method to purge fuel tanks. I have contemplated methods to safely weld a gas tank, I am going to have to at some point, honestly feel that rinsing with soap and water first, then verifying lack of explosive vapor with fire is probably the safest/easiest way for someone doing this at home to do so.

I fail to see a safety risk if the tank is rinsed first with soap and water, then checked with an ignition source from a distance. Even if there is vapor present after rinsing, the amount present would be exponentially less (meaning the startling caused by the ignition test wouldn't be so bad).
 
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if soap / water i find basic old blue dawn dish soap is best. its also the kind the clean up teams use on animals in oil spills.

be carefull as we had a guy around here years ago welding on 1 in his basement. he is now dead . . . .

and if you can get reg solder get it with acid core . works better on metals .
 
If you wanna clean it out, put some muriatic in it. Let it sit for a while, rotate it every so often so that it sits on all surfaces of the tank. Then, I would recommend soldering it. At the rad shop, we use a lead solder. We've done hundreds of gas tanks this way, with no problems. Just make sure you neutralize the gas fumes somehow. You can hook up a hose from your cars tailpipe and put it into the tank and this will purge all the gas fumes.
 
sweetk30 said:
if soap / water i find basic old blue dawn dish soap is best. its also the kind the clean up teams use on animals in oil spills.

be carefull as we had a guy around here years ago welding on 1 in his basement. he is now dead . . . .

and if you can get reg solder get it with acid core . works better on metals .
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Well I will be doing it in the middle of my yard with 3 fire extinguishers all manned and ready to go at a safe distance.

80' 427 said:
Have a rad shop boil it out and solder it?
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I will have to call one and see what they say.
 
Don't weld it. I agree that is the strongest joint, but its already been soldered, and the lead in the joint is going to make welding really hard.

Radiator shop is the way to go if one is around. Plus if its a galvanized tank, the muretic acid will remove all the galvanize.

If you had one of those old fashioned flame heated soldering irons, you could have the flame a ways away from the tank, and only have to bring the heated iron over to do the soldering.
 
Radiator shops around here won't touch gas tanks I found out today.

So thats out. So off to see if I can find some solder then.

How hot does the flame need to be for the lead solder?

rosebud on the torch hot, mapp gas torch hot, propane torch hot? Big soldering iron hot?
 
blazinzuk said:
Radiator shops around here won't touch gas tanks I found out today.

So thats out. So off to see if I can find some solder then.

How hot does the flame need to be for the lead solder?

rosebud on the torch hot, mapp gas torch hot, propane torch hot? Big soldering iron hot?
Click to expand...

Eric, you should be good with the propane torch. It needs to be hot, but not so hot that it will warp anything. If I were you I would test it out so you can see. Thats weird that a rad shop wouldn't do it.
 
I had a body shop guy I knew solder up my leaky gas tank in my Chevelle wagon,after getting tired of trying to seal it up with fiberglass cloth and resin more than once--it always leaked again 6 months later,right where the tire tosses stones at it,and water collected in the lowest corner..no one else in town I asked would even consider doing it..

He just told me to get all the gas out as best I could,fill it with water from the garden hose and let it overflow (where no grass is wanted to grow),and then leave it in the hot sun for a day or two...when he went to solder it,he squirted his CO2 fire extinguisher into the tank,a good 4-5 second blast,then put the cap on the tank and soldered it with 50/50 acid core solder,using "tinners flux".which I think is hydrocloric acid..
I waited a few hundred feet away while he soldered it!..:eek:...no problems though...it never leaked again where he soldered it,but a new spot began weeping a few months later...:doah:

I remember an clever old guy I knew who taught me a lot of things about cars when I was a kid,fixing a leaky tank in my brothers '63 VW beetle one day...it had a pinhole at the bottom of the tank,and you could get at it easily without having to pull the tank out...he said "I can fix that drip in 5 minutes,without taking the tank out"...

He had us jack it up,and he took his torches and found a large bolt about 5/8" and clamped it in a pair of vise grips,and he heated the head of it up bright orange..then took a shiny new penny out of his pocket,and placed it on the head of the bolt--tinned the penny with flux and acid core solder,and then wiped some flux on the tank where it was dripping slowly...and he pressed it against the tank and held it there,and it went
"SSSSSSSsssssssssssssss"...held it there for about 3 minutes,to be sure the solder had cooled off enough to harden up--the thing never dripped again the 2 years my brother owned that car...I've never been brave enough to try that myself,but probably will someday...
 
It's kinda like sweating copper pipes with solder. Clean it really good and use lots of flux. Just heat up the metal with the flame and remove the flame. If its red, its too hot.

Then touch the solder onto the metal. If it melts readily, it should wick into the joint all by itself. If it doesn't melt readily, add a little more heat and repeat until it does. Just don't ever put the solder wire into direct flame. The goal is to heat the metal and let the metal soak up the solder with capillary action.
 
had a guy on the ranch who would pull the tank, drain it, start another truck and run a hose from the exhaust pipe to the filler neck on the tank to be welded. let it run for a couple minutes and with the hose still hooked up, weld the hole up.

bu he wasnt welding the filler neck its self.
 
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